Contact Lists no longer available in Outlook for Windows 10 Mobile?

[Windows Central Question]

In Outlook for Windows 10 Mobile, I used to be able to create a new email, and input the name of a Contact List into the "To:" field. However, this is no longer recognized. The "To:" field now only recognizes individual Contacts. When did this change? Is there a way to fix this? This still works on Outlook.com (OWA).